LEDs are semiconductor devices that emit lights when an electrical current is supplied thereto. As shown in FIGS. 1a and 1b, typically, an LED 100 is formed of multiple layers of materials having a layer of p-doped material or p-type semiconductor layer (“p-layer”) 101, a layer of n-doped material or an n-type semiconductor layer (“n-layer”) 103, and a light generating region or p-n junction 105. When powered, the p-n junction emits lights in a primary direction 107 towards one of the p- and n-layers creating a field of illumination 109 roughly along a longitudinal axis parallel to the direction 107.
In certain applications of LEDs, for example in a backlight illumination system, it may be desirable to convert the LED's light illumination field 109 into a “bat-wing” light illumination field 201 as illustrated in FIG. 2. Conventionally, complicated optical designs have been adopted in the packaging of the LED, which may make the LED packaging unnecessarily bulky.
It is an object of the present invention to provide a light emitting device, which overcomes at least some of the deficiencies exhibited by those of the prior art.